1. Field of the Invention
The present invention generally relates to finishing printed sheets of paper and, more particularly, to hole-punching folded sheets of printed paper.
2. Background Information
A system for finishing printed sheets into booklets is described in U.S. Pat. No. 6,099,225 (Allen et al., hereafter referred to as xe2x80x9cthe Allen patentxe2x80x9d), hereby incorporated by reference in its entirety, where most finishing operations are performed on a sheet-by-sheet basis using precise paper positioning. The system also uses a transverse tool carrier for cutting, scoring, folding, punching, and stapling booklet sheets. The Allen patent does not specifically address the issue of aligning hole locations from one booklet sheet to another when individual sheets are being punched.
Another system for assembling sheets of printing media for booklets is described in PCT No. WO 00/18583 (Trovinger et al., hereafter referred to as xe2x80x9cthe Trovinger PCTxe2x80x9d), hereby incorporated by reference in its entirety. The Trovinger PCT includes an operation where either a single booklet sheet or a collected stack of booklet sheets is punched (or drilled) to form holes, e.g., to allow storage in a three-ring binder. In the Trovinger PCT, individual printed sheets undergo a punching operation prior to a folding operation. If a completed booklet is to be placed in, for example, a three-ring binder, six holes would need to be created in each flat, pre-folded booklet sheet (i.e., three holes per each side or xe2x80x9cpagexe2x80x9d), an operation requiring six punch actions. Also, the Trovinger PCT does not specifically account for the alignment of hole locations from one booklet sheet to another when individual sheets are being punched. In the alternative hole-punching operation, where booklet sheets are to be punched together as a collected stack, relatively high forces are needed to force sheet materials through multiple pages of a booklet.
Accordingly, what is needed is a low-cost and efficient process for hole-punching booklet sheets, requiring less and lower-force punch actions, and providing sheet-to-sheet hole alignment.
The present invention is directed to hole-punching folded booklet sheets in a sheet-wise booklet making system, where sheet information associated with each booklet sheet is used to determine the locations on the booklet sheet where holes are to be created.
According to a first embodiment of the present invention, a method of forming booklets is provided, comprising the steps of folding sheets, punching the folded sheets individually at hole punch locations determined based on sheet information, stacking the punched sheets, and binding the stacked sheets in a booklet.
According to a second embodiment of the present invention, a hole-punching apparatus is provided, comprising a clamping device, a drive system, wherein a folded sheet is held stationary by the clamping device on a first side and is driven by the drive system on a second side, and a punch tool having a hole punch, wherein a folded edge of the folded sheet is positioned relative to the hole punch based on the driving of the second side of the folded sheet.
According to a third embodiment of the present invention, a method of hole-punching booklet sheets is provided, comprising the steps of holding stationary a leading side of a folded sheet, driving a trailing side of the folded sheet such that a folded edge of the folded sheet is moved into a punching device, wherein the trailing side is driven based on position information and sheet information, and punching at least one hole in the folded sheet with the punching device.
According to a fourth embodiment of the present invention, an apparatus for hole-punching booklet sheets is provided, comprising means for punching a hole in a folded sheet, means for holding stationary a leading side of the folded sheet, and means for driving a trailing side of the folded sheet such that a folded edge of the folded sheet is moved into the means for punching, wherein the trailing side is driven based on position information and sheet information.